<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>Title</title>
    <script src="jquery-3.3.1.min.js"></script>
</head>
<body>
<h1>1</h1>
<h2>2</h2>
<h3>3</h3>
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</body>
</html>